Various devices are known for isolating a retentate containing a high molecular weight material, such as DNA or protein, through centrifugal ultrafiltration. The yields and amounts of retentate achieved using these techniques vary greatly due to the size, shape and position of filter membrane, the positions of outlets and/or the presence of ledges, comers or compartments in the devices.
Often these devices have associated limitations or drawbacks. For example, a device may be ineffective to prevent filtration of retentate to near dryness, or may have a design that hinders access to, or prevents complete pipette recovery of, the retentate due to chamber geometry, surface tension spreading, or the like. Also, a device may attain only a low yield or poor separation, or may require excessive centrifuge times. Additionally, a device may be poorly adapted for, or entirely incapable of, being prepared by or being used with robotic or other automated devices. Further, a technique or device may be uneconomic due, for example, to inefficient utilization of filter membrane area, and/or to manufacturing cost, and/or to requiring a long centrifuge time.
Therefore, a need exists for a centrifugal ultrafiltration device that can be dependably manufactured and used.
There is also a need for a separation technique that is rapid, effective and amenable to automated implementation.
There is also a need for improved processes for the manufacture or assembly of filtration or concentration vessels.